Setting head for machines for the grinding of worms



Dec. 3, 1935. LECHESNE 2,023,329

SETTING HEAD FOR MACHINES FOR THE GRINDING OF WORMS Filed March 16, 1935 3 Sheets-Sheet l Deb. 3, 1935. 1 LECHESNE 2,023,329

SETTING HEAD FOR MACHINES FOR THE GRINDING OF WORMS Filed March 16, 1955 s Sheet-Sheet 2 [NJ/M7; Gan'el lecesize.

G. LECHESNE Dec. 3, 1935.

SET'I 'ING HEAD FOR MACHINES FOR THE GRINDING OF,WORMS Filed March 16, 1935 5 SheetsSheet 3 Jul 611252; Garzd Zea/wane.

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Patented Dec. 3, 1935 UNITED STATES SETTING HEAD FOR MACHINES FOR THE. GRINDING F WORMS Gabriel Lechesne, Montreuil-sous-Bois, France, assignor to Paul Durand, Neuilly-sur-Seine,

Seine, France Application March 16, 1935, Serial No. 11,485

4 Claims.

'I'he present invention relates to worm gear grinding machines wherein an abrasive wheel is employed and more particularly to an attachment or setting head for such machines wherein the grinding or cutting surfaces of the abrasive wheel may be reset or kept in proper form for grinding the gears while the machines are in operation.

Among the principal objects of the invention is the provision of an attachment for worm gear grinding machines which may be easily and readily applied thereto having adjustable cutting tools which latter may be kept in the proper cutting contact with the grinding wheel of such machines ;whereby the various grinding surfaces of the character comprising a rocking cradle, which en- Another feature of the invention consists of a carriage mounted on the above-mentioned cradle and is comprised of a detachable guide-piece or gauge, which acts on the tool, mounted on the said carriage, for the grinding of the bevelled face, in order to give to this face the profile of the gauge.

Still another feature of the invention consists in that the head is movable on the framework of the machine, so that it can be adjusted to the various diameters of grinding wheels employed and that it can be used at the same time as a support for the guards for the protection of the operators.

Finally, the invention embraces the characteristics and the details of the means which are clearly set out in the following description and in the accompanying drawings. In these drawmgs:

Figure l is a perspective view of the setting head constructed in accordance with the inven-. tion applied to .a worm gear grinding machine.

Figure 2 is a side view of the setting head as applied to a grinding machine, but showing the grinding wheel thereof in section.

Figure 3 is a detailed front view of a portion of the grinding wheel and a vertical transverse section through the setting head or attachment for the grinding machine.

The mechanism or setting head is formed by a carriage I provided with grooves, which slides on the guide-rails 2 mounted on the grinding machine 3 (Figures 1 and 2).

The holding carriage I can therefore, owing tothe said guide-rails, move vertically along an axis which is perpendicular to the shaft 4 of the grinding wheel, by reason of a rack 2a which is integral with the guide-rails and a toothed pinion 2b controlled by a wheel 5.

On the shaft 4 there is mounted a plate 611, 5 which has an annular recess in which there is arranged a grinding wheel 6 formed of abrasivematter.

The wheel 6 is intended for the grinding of worms 1, which are held in the machine by means 10 of suitable adjustable members. For this reason the said wheel 6 has a profile comprising an inner face 6b, a side face 60 and a bevelled face 6d having an appropriate curvature for grinding one of the flanks of the threads of the screw 1 without the faces 6c and 6d entering into contact with the flank of the adjacent screw.

The holding carriage I, the height of which is varied according to the diameter of the grinding wheel 6, is constructed so as to have a semicylindrical cage Ia at its upper part.

On this semi-cylindrical cage Ia a cradle 8, the base of which is also semi-cylindrical, can slide.

This sliding movement is guided by a grooved rail 9 (Figure 3) and by a flat rail Ill. The cradle 8 is held in the selected position on the carriage I, by means of locking bolts II passing through the grooves I2 arranged in the cradle.

The movements of the cradle 8 relatively to the carriage I are marked by means of a graduated arc I3 fixed on one of the members and a Vernier I4 fixed on the other.

In the cradle 8 and parallel to the shaft 4 of the grinding wheel there are provided two dove- 3 tail-shaped guide rails I5, between which there slides a carriage I6.

This carriage has mounted on it a housing I! which is arranged perpendicular relative to the said carriage.

22 having projecting ends 24 which extend through vertically elongated slots 25 and 26 formed within the housing II. Carried by one of the projecting ends of this spindle isa roller 23.

The piston I8 is displaced vertically in the housing I! under the force of the roller 23 guided by the sinuosity of the cam 21. This vertical displacement of said piston I8 is guided by the projecting end 24 moving in the elongated slots 26 of the housing I1.

As it is necessary for the grinding of worms 6d which alone does effective work and which requires resetting in accordance with the extent to which it is used.

For this purpose the piston 18 is provided with a clamping chuck 28, which receives a diamondholder 29. The diamond 30 must be able to come into contact with the part 612 in order to re-set it.

Consequently the part 60 also must always be re-set to an extent which depends upon the treatment of the part Ed by the diamond 30. For this purpose, there is provided on the side of the cradle an internal boss 3| in which there slides a small piston 32 carrying a diamondholdlng tool 33.

A spring 34 tends constantly to lift the piston 32 and to withdraw the diamond 35 from all contact with the grinding wheel 6.

The top of the piston 32 is fitted with a ball and socket joint-box 36, in which there is fitted the end of a ball and socket lever 31.

The lever 31 rocks about a spindle 38 and has a handle 39, which can be grasped outside the machine. The spindle 38 is mounted in the cradle and it is therefore possible, by actuating the lever 31, to cause the lever 32 to descend when required and, in consequence, the diamond 35.

The movements of the carriage 16 on the cradle 8 are obtained by means of a lever 40, which is pivoted about a pin 4| which is integral with the .cradle and acts in the same way as the lever 31 on a ball and socket joint-box arranged in the carriage l6 and not shown in the drawings.

The gauge 21 is mounted in a small carriage 42 by means of fixing screws 43. The carriage 42 runs on a rail 44 provided on the cradle 8. It is held stationary on this latter by means of a locking screw 45, the head of which runs in a T- shaped groove 46 provided in the cradle.

The movements of the carriage 42 relatively to the cradle are ascertained on a graduated arc 41 and a scale 48 arranged on the two pieces.

It will thus be seen that it is easy, owing to the circular movement of the cradle 8 and to the tangential movement of the carriage l6 relatively to the said cradle, to move the two diamonds 30 and 35 in such a way that their points come into coincidence, in the position for starting Work, at the intersection of two perpendicular planes aa and bb (Figs. 2 and 3), which cut one another at the angle formed by the parts 6c and 6d of the grinding wheel.

From this starting position, by actuating the levers 31 and 40 the diamonds can be moved against the grinding wheel 6.

The diamond 35 will move vertically so as to effect the re-setting of the fiat part 60 of the grinding wheel.

The diamond 30 will move over the part 6d of the grinding wheel in accordance with the curvature of the gauge 21 on which the roller 23 of the diamond-holding piston l8 moves when the carriage l6 moves over the cradle 8.

With this device it is possible to insure a constant rational shape and, diameter of the grinding "wheel 6 which enable a correct grinding of the worms to be carried out owing to the working of the part 8d of the grinding wheel against a single side of the screw thread.

The carriage l is provided with fins 49 on which there may slide protecting aprons 50 fixed on the said wings by means of screws passing through the groves 52 arranged in the aprons.

Finally the cradle 8 is provided in front with a protecting screen 52. 5

The complete head of the machine therefore serves at the same time for the re-setting of the grinding wheel and as a protecting means for the workers against accidents which might be caused by chippings at the time of the said re-setting.

What I claim is:

l. The combination with a worm gear grinding machine having included therein a grinding wheel having a desired profile, means for keeping said profile comprising cutting tools, means carrying and guiding one of said cutting tools, means mounted on said machine on which said carrying means slides along an arc of a circle having as its center the intersection of the plane of the front face of said wheel profile and the plane of the external bevelled face of said wheel profile and means holding and guiding the other of said tools for the resurfacing of the side face of said wheel profile.

2. The combination with a worm gear grinding machine comprising a wheel having an annular groove formed in one face thereof, abrasive member mounted within said groove having grinding faces which at times require resetting, of an adjustable support, a cradle adjustably mounted upon said support, cutting tools for resetting the several grinding faces of said abrasive member,

a manually operable member for moving one of said tools into and out of cutting position with respect to one of the grinding faces of said abrasive member, a carriage slidably mounted upon said cradle, a vertically movable piston carrying the other of said cutting tools and adjustably mounted within said carriage, a gauge adjustably mounted upon said cradle for controlling the vertical movement of said piston, and a lever adjustably mounted upon said cradle whereby said carriage may be manually moved.

3. The combination with a worm gear grinding machine having included therein a rotatable wheel carrying an annular abrasive member for grinding the gears, of means for resetting the grinding surfaces of said abrasive member comprising a. cradle arranged above said wheel, means for adjustably supporting said cradle whereby it may oscillate over said wheel, a carriage slidably mounted upon said cradle, a piston vertically movable within said carriage, a gauge adjustably mounted upon said cradle, guide rollers projecting from said piston and adapted to ride 55 upon said gauge, a cutting tool carried by said piston, and a manually operable lever connected to said carriage.

4. An attachment for worm gear grinding machines comprising a support, an arcuate guide 0 carried by said support, a cradle adjustably mounted upon said guide, said cradle having laterally arranged grooves therein, a carriage slidably mounted within the grooves of said cradle,

a piston vertically movable within said carriage, 5 a cutting tool carried by said piston, manually operable means for controlling the vertical movement of said piston, a gauge adjustably mounted upon said cradle, means carried by said piston and adapted to ride upon said gauge, and a manually operable lever connected to said carriage.

GABRIEL LECHESNE. 

